Booking Back AS Process Object Licenses and Managing License Recovery in SIMATIC PCS 7

In SIMATIC PCS 7, downloading an Automation Station produces the warning 'process objects should have been booked back with this download... could not be booked back' when the target controller was originally programmed from a different project database or when project binding signatures are lost. Automation Station Runtime Process Object (AS RT PO) licenses are tied to specific project-CPU pairings; recovering unbooked POs requires compiling and downloading from the original multiproject or reconciling license accounts via SIMATIC Manager License Information.

Architecture of Process Object Licensing in SIMATIC PCS 7

SIMATIC PCS 7 implements a structured, multi-tier licensing model that strictly distinguishes between engineering authorizations, controller runtime capacities, and supervisory operator station limits:
* AS Runtime Process Objects (AS RT PO): Software runtime licenses managed in Automation License Manager (ALM) on the Engineering Station. Any CFC block with message capability (e.g., PIDConL, MotL, VlvL) and operator control/monitoring capability consumes exactly 1 AS PO. Redundant AS systems consume AS RT POs only once from a common project pool.
* CPU 410 System Expansion Card (SEC): A separate hardware capacity license embedded in the physical CPU 410 SEC card (ranging from 100 PO to 2600+ PO). SEC capacity determines the physical limit of the controller and is distinct from software AS RT PO licenses.
* OS Runtime Process Objects (OS RT PO): Separate runtime licenses on WinCC OS servers based on WinCC process tag objects.
* OS Archive Licenses: Tag logging archive limits licensed separately from process objects.

Mechanics of PO Booking and Booking Back During AS Download

When you compile and download CFC charts to an Automation Station:
1. Compilation Accounting: The CFC compiler calculates the exact number of instantiated technological blocks that meet PO criteria.
2. Booking Out: During initial download, the Engineering Station checks Automation License Manager (ALM) for valid AS RT PO license keys. The required PO quantity is deducted from the available license pool on the ES and recorded in the target CPU's internal system data block alongside a unique project identification GUID.
3. Booking Back: If you delete charts, remove technological blocks, or download an empty project to clear the CPU, the ES compares the new lower PO requirement against the controller's recorded PO count. The difference is "booked back" (returned) to the ALM license key on the Engineering Station.

Root Cause of the Error: 'PO Could Not Be Booked Back'

The diagnostic error message:

83 process objects should have been booked back with this download. 83 of these could not be booked back.

occurs under specific operational circumstances:
* Project Discrepancy: The target CPU currently contains a program downloaded from Project A (or an earlier unarchived copy), but an engineer is downloading from Project B. Because the internal project GUIDs do not match, the ES refuses to book POs back into Project B's license ledger to prevent cross-project license duplication.
* Restored Project Without License Tracking Data: If a project was copied using raw Windows Explorer folder copy rather than SIMATIC Manager File -> Archive, the hidden PO accounting database files (.po records) may be missing or desynchronized.
* Missing License Keys in ALM: If the original AS RT PO license key was moved to another workstation or uninstalled from ALM, the system cannot credit unbooked POs back to a non-existent key.

Step-by-Step Procedure to Recover and Reconcile AS RT PO Licenses

To successfully return POs and reconcile licensing ledgers:
1. Locate Original Project: Always download an empty or clean program from the exact original multiproject that originally booked out the POs.
2. Empty Program Download:
* In the original project, create an empty CFC chart or delete the retired chart partitions.
* Execute CFC -> Compile -> Entire Program.
* Download the entire program to the target CPU. The ES recognizes the matching project GUID and books the freed POs back into ALM.
3. Reconcile via License Information Tool:
* In SIMATIC Manager, select the root project folder.
* Navigate to Options -> PCS 7 License Information.
* Select Process Objects (AS).
* Review the table showing: Configured POs, Booked POs, and Available POs in ALM.
* If a discrepancy exists, click Check / Update to synchronize the ES database with ALM.
4. Clearing Lost Controller Binding:
* If the original project is completely lost, perform an overall CPU reset (MRES) with a memory card wipe, or download the new project.
* Note that unrecovered POs from a permanently lost project database cannot be credited back automatically; in such scenarios, contact Siemens Customer Support with your original Certificate of License (CoL) details for license reconciliation assistance.

Verification

In SIMATIC Manager, open Options -> PCS 7 License Information -> Process Objects (AS).
Verify that the column Total Available POs in ALM reflects the expected license count.
In Automation License Manager, select the active license drive and verify that the SIMATIC PCS 7 AS RT PO key shows 0 missing counts.
Perform a delta compile and delta download on the active project: confirm that no booking warning dialog appears.

Limitations and Operational Precautions

Never use Windows Explorer to manually copy or merge PCS 7 project folders containing booked POs; always use File -> Archive and File -> Retrieve in SIMATIC Manager.
Never infer licensing requirements solely from rough I/O ratios or tag counts. Actual PO consumption is established exclusively by the CFC compiler and verified via SIMATIC Manager License Information.
For redundant AS pairs, POs are shared; do not attempt to double-book POs on redundant partner CPUs.

Engineer FAQ

What constitutes a Process Object (PO) in an S7-400 Automation Station?
A technological block that has alarm generation capabilities, is controllable/monitored by an operator, and typically connects to field I/O (e.g., motor, valve, PID).
Do channel drivers (e.g., Pcs7AnIn, Pcs7DiIn) consume AS Process Objects?
No, pure signal channel driver blocks and mathematical calculation blocks (e.g., Add04, Mul04) do not consume AS Process Objects.
How do I check the exact PO consumption of a single CFC chart?
In CFC, select Chart -> Chart Reference Data -> Statistics to view technological block counts and PO consumption.
Does CPU 410-5H require both an SEC card and AS RT PO licenses?
Yes, the physical CPU 410 SEC card establishes hardware execution capacity, while the AS RT PO license authorizes software runtime POs in ALM.
Can POs be transferred from an AS license to an OS license?
No, AS Runtime POs and OS Runtime POs are separate software packages and cannot be exchanged or converted into each other.
Does a redundant AS pair require two separate AS RT PO license packages?
No, in PCS 7, a redundant AS pair (e.g., AS 410H or S7-400H) consumes AS RT POs only once from a shared project pool.
What happens during runtime if an AS program exceeds available AS RT PO licenses?
The compiler and download wizard will issue license shortage warnings. The CPU will continue running, but the system enters a non-compliant license deficit state logged in ALM.
Where are AS RT PO licenses physically stored?
They reside as license keys on the Engineering Station's hard drive or network license server managed by Automation License Manager (ALM).
Why does downloading a program to a brand-new spare CPU book out POs?
Because the spare CPU has an empty system data block, requiring initial PO deduction from the ES license pool to authorize the download.
What should I do if a hard drive crash destroys the ALM license key with booked-out POs?
Use the official Siemens License Key Recovery procedure via Automation License Manager and Siemens Customer Support using your original Certificate of License.

Technical References

SIMATIC PCS 7 Licenses and Configuration Limits Manual (V9.0 / V9.1)
SIMATIC PCS 7 Engineering System Manual (V9.0 SP3 / V9.1)
Siemens Industry Online Support Entry: Process Object Booking and Recovery (Entry ID 298587)
Siemens Industry Mall: SIMATIC PCS 7 AS Runtime Licensing Structure

Related Tags

PCS 7, Process Objects, AS RT PO, Licensing, ALM, CPU 410, SEC, Booking Back, SIMATIC Manager, Compliance

Booking Back AS Process Object Licenses and Managing License Recovery in SIMATIC PCS 7